The purpose of this study is to demonstrate that a preventive network of care for asthma that links the family, the child's physician, and the school can improve the health status of children with asthma. The New York City Bureau of School Children and Adolescent Health (BSCAH), the New York City Board of Education (BOE), school nurses and primary care physicians, and the investigators will collaborate to form a network of care focusing on preventive aspects of asthma to identify children with asthma in the school, and work with the family and the physician to develop an asthma management plan for each child including supervision of medicine-taking at school. The study will focus on children with poorly controlled asthma. The network will offer to physicians, who treat children with asthma at school or a nearby practice, continuing medical education in cooperation with Columbia University based on the NAEPP guidelines for asthma care. The project will refer children who lack continuing care to physicians who practice under NAEPP guidelines. Furthermore, they will teach BOE teachers and other school staff to respond appropriately to children with asthma and will provide health education to help the child and family manage asthma. The network will work with BOE and Columbia to develop classroom lessons on the biology of breathing and asthma for all children in school. There are two phases in the proposed research. In Phase 1, pilot work in eight schools will be done to create a preventive network of care using methodology that has been developed in preliminary studies. Phase 2 consists of a controlled trial in 40 schools matched and randomly assigned to intervention and control status. The investigators hypothesize that relative to controls the children in the 12 intervention schools will have less asthma morbidity, fewer days of limited activity, improved school attendance and performance, and improved quality of life.